New rear sprocket???
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Nobody ever said that they would last forever, Eddie.
But, there are definately things you can do to help make them last longer. And to deny that is kidding yourself.
Your pistons, cranks, rod bearings, wheel bearings, linkage bearings, cables, or any other mechainical part of your bike isn't going to last forever either, but are you foolish for not trying to maintain them in the best way possible? Or do we just turn our heads to good and proper maintenance and let the chips fall were they may?
But, there are definately things you can do to help make them last longer. And to deny that is kidding yourself.
Your pistons, cranks, rod bearings, wheel bearings, linkage bearings, cables, or any other mechainical part of your bike isn't going to last forever either, but are you foolish for not trying to maintain them in the best way possible? Or do we just turn our heads to good and proper maintenance and let the chips fall were they may?
regarding the chips falling, that would be a function of floor cleanliness, times a constant "k" which is 3.4192 squared, times the "three second rule". :p
the chain care debate reminds me a bit of how I called my neighbors "idiots" and some other more colorful names. They are renting the place and refuse to do any yard work. All of their leaves blow into my yard. Certainly they don't expect me to rake leaves FOR them, they probably think i am an idiot for raking at all. I have now realized they aren't really idiots, they just have different priorities. The ends don't justify the means for them, just like intensive chain maintenance isn't a priority for many riders, due to time vs. money factor. Heck, there are folks out there that buy a new bike and don't do ANYTHING besides put gas in it, ride it for a year or two then sell it and buy another new one...buyer beware!
regarding chain pitch, Jaybird, I realize as a chain wears or stretches it gets longer. But if that is 100% wear and 0% stretch, the chain wouldn't necessarilly ride any different on the sprocket.
think of it this way, when measureing that worn chain, if we stretch it out it measures over pitch, but if we push all the links together it will measure under pitch.
the problem lies in the fact that the pin to bushing clearance is now greater, and only the first roller or two is actually contacting the sprocket and pulling it, even though the remaining rollers may ride in the "normal" spot. With an aluminum sprocket, I suspect rather than purely wear from friction, we are also looking at plastic deformation of the working surface of the tooth. Note the rolled over edge or burr.
the chain care debate reminds me a bit of how I called my neighbors "idiots" and some other more colorful names. They are renting the place and refuse to do any yard work. All of their leaves blow into my yard. Certainly they don't expect me to rake leaves FOR them, they probably think i am an idiot for raking at all. I have now realized they aren't really idiots, they just have different priorities. The ends don't justify the means for them, just like intensive chain maintenance isn't a priority for many riders, due to time vs. money factor. Heck, there are folks out there that buy a new bike and don't do ANYTHING besides put gas in it, ride it for a year or two then sell it and buy another new one...buyer beware!
regarding chain pitch, Jaybird, I realize as a chain wears or stretches it gets longer. But if that is 100% wear and 0% stretch, the chain wouldn't necessarilly ride any different on the sprocket.
think of it this way, when measureing that worn chain, if we stretch it out it measures over pitch, but if we push all the links together it will measure under pitch.
the problem lies in the fact that the pin to bushing clearance is now greater, and only the first roller or two is actually contacting the sprocket and pulling it, even though the remaining rollers may ride in the "normal" spot. With an aluminum sprocket, I suspect rather than purely wear from friction, we are also looking at plastic deformation of the working surface of the tooth. Note the rolled over edge or burr.
So anyway the Sprocket specialist sprocket I have is the SX series. It is not the two materials bonded together type.. Actually I have them on my 450 for about 6 months riding about twice a week. I noticed this weekend the chain is just about gone. if you pull back on the chain midway on the sprocket the rule is half or less of the tooth should be visible any more and the chain is likely toast. Well half the tooth is exposed now. The sprocket doesnt look too bad though so I am thinking about just replacing the chain cause it just happened and it is early in the wear cycle. I had a KDX with Sidewinder steel sprockets which I put on immediately when I got it and I had the bike for three years. I rode hard on sand , and mostly in mud but I went through two chains and the sprocket never even looked worn in the least when I sold the bike I dont think it will wear out in ten years. I didnt put them on this bike cause I wasnt sure if I wanted to stay with this gearing for a long time, which I dont. Generally if such a hard sprocket is not used the chain and sprocket must all be replaced at the same time. at the very least the chain may be replaced if the sprocket isnt worn but anytime the sprockets are replaced the chain should be replaced. I have seen it many many times you will see a dramatic increase in the time it takes to wear out your drive system if you dont. To me it is like replacing only the inner race on a bearing and not the outer one.
You asked for it, and I gave it to ya. :)motometal said:
It really doesn't take much time to maintain your drive properly. You simply need to know how to do it. But I agree, some have different priorities.motometal said:
Brand new side plates will have a minimal amount of elongation due to the metal actually stretching. But initial stretch is very very minimal, and many mfg's are now "proof stetching" the chains at build to eleminate the consumer having to make any adjustments due to this stetch.motometal said:
But I completely disagree with you on where the chain rides when it elongates. It is a fact that the chain will not ride as intended when it elongates.
No, it will not measure under pitch by "pushing" the chain together. Take a stretched chain apart and you will see that the pin has only one area of the circumference that has a worn spot on it. These worn spots will always be to the inside of the link. There will also be worn spots on the bushings, but they will always be on the outside of the bushing reel. Only if the wear was around the total circumference of the pin or bushing would what you say be true.motometal said:
When a stetched chain is on a new sprocket set, or a hard sprocket set that has no deformation of the teeth, the teeth have a very hard time meshing with the links. The driver has trouble gettin into the link, and the driven has a hard time getting out of the link. And I agree that with this, the sprocket teeth can become compressed and deformed from it, but it is still wear due to pitch variance. The brute force of the bike will not deform a perfectly matched pitch set. However, when the chain has elongated, then the force of the bike does in fact come into play and helps accelerate the demise of the teeth.motometal said:
Take a hard sprocket set-up and mount a chain that has a pitch of more than 2% new. You will notice that it makes alot of noise when you spin it. Also, it will not spin freely...it stops very soon. Now mount a good chain and spin away. Less noise and keeps spinning.
(Scott...I will give you an E for effort. :flame: )
GREENBEAN,
Pulling the chain away from the sprocket to check elongation is a junkyard way to measure and is hardly accurate. Although, due to the chain not being of the original pitch, you can pull it away from the sprocket. Learn the correct way to measure a chain.
Also, there is no reason whatsoever to change out a sprocket that has no wear on it. It is good rule of thumb to change out both because many run both till they are trashed.
If you have a theory on why we should do this, I'm all ears.
ok, you got me on one point, the chain won't measure under pitch if pushed together. I'm more sober now and it makes more sense :eek:
my point was, that if the chain is strictly worn and not stretched, it can still ride on the sprocket in the "normal" position. Granted, all of the force would be on the first few leading teeth. The tension of the chain, or gravity may make it ride up on the back side of the sprocket. I'm glad you brought this up, because I never really though about why the chain would ride on the sprocket the way it does when it's worn.
Also, some times when the chain and/or sprockets are really bad, rolling the bike backwards makes all sorts of racket and binding. Does this mean the teeth are "hooked"?
my point was, that if the chain is strictly worn and not stretched, it can still ride on the sprocket in the "normal" position. Granted, all of the force would be on the first few leading teeth. The tension of the chain, or gravity may make it ride up on the back side of the sprocket. I'm glad you brought this up, because I never really though about why the chain would ride on the sprocket the way it does when it's worn.
Also, some times when the chain and/or sprockets are really bad, rolling the bike backwards makes all sorts of racket and binding. Does this mean the teeth are "hooked"?
It all has do do with the working face of the tooth comming in contact with the out-of-pitch chain. On the driver, it's pushing on the reels. On the driven, the reels are pulling on the tooth face.
When you reverse a worn drive, you have the opposite working faces, that are not worn, coming in contact with the out-of-pitch reels. Makes mucho racket.
The driven sprocket becomes the driver, if you will. The pitch on the sprocket has now changed back to new...and since the chain stays a constant, it doesn't match any more like the worn chain and worn sprocekt teeth.
If you powered this action, it would most likely break the chain.
When you reverse a worn drive, you have the opposite working faces, that are not worn, coming in contact with the out-of-pitch reels. Makes mucho racket.
The driven sprocket becomes the driver, if you will. The pitch on the sprocket has now changed back to new...and since the chain stays a constant, it doesn't match any more like the worn chain and worn sprocekt teeth.
If you powered this action, it would most likely break the chain.
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Thats a good guide for measuring chain stretch there. I wonder if there is a way to measure the deformation that occurs to the roller face. That would seem to be a proper way to measure the actual wear of the chain and not just the stretching of the chain. :think: If those surfaces are worn then the surface area in actual contact with the sprocket face is different than originally intended.
JAYBIRD,
Take into account This is the actual thing smashing or working the face of the sprocket. If those surfaces start out new together in harmony then they will probably go through some plastic deformation together and find a happy place. That is when work hardening occurs and your chain stops initially stretching. The rest of the wear would seem to be on the roller pins and faces of the rollers which is why you have to hang a weight to measure the length of the chain. That deformation that occurs on the face of the chain roller which may have not stretched because of a say, pre stretched chain or the egging of the roller itself may not be easily detected by just looking at the chain or even measuring length.
The sprocket can be worn out at an especially faster rate especially if it doesnt perfectly match the surface of the chain rollers starting the rolling wear or bulging you see which occurs on the junky aluminum sprocket variety. My theory of "Junkyard style" home grown chain measurement I have distilled for 22 years is based on first having a superior steel sprocket which never ever ever ever wears out of course. First I do a sag measurement. The chain which actually could be worn out even though it may still measure to be in the 2% range. But you say why it can never wear out it is Pre stretched and those plates are onobtanium and will never stretch, Hmm or did it already stretch and deform in length.. Second I just takes me finger and I just pull that chain back and it tells me if the chain is still in pitch, quickly. This also tells me if the rollers are making good contact with the sprocket gear tooth faces. Of course Jaybird measuring the length of the chain will tell me if the chain stretched but not if the chain rollers are eggs and wont fit in the sprocket anymore and fitting good. If the sprocket is being changed and the chain was used for any reasonably long time. I know that those sprocket rollers were deformed they have to be pal and I am not going to ruin a new sprocket by putting it on there if I cannot measure the actual rollers for wear. IF you have a theory on knowing if the rollers are worn and not just if the chain is stretched I am all ears.
I personally wouldnt trust dual material sprockets because I would guess that the shear forces are too great between the two materials. Actually they would be multiplied as the connection between them is further out from the center. That any weight savings would be lost by trying to efficiently and safely engineer a bond or connection between the two materials and actually save any weight. I need another beer now.
JAYBIRD,
Take into account This is the actual thing smashing or working the face of the sprocket. If those surfaces start out new together in harmony then they will probably go through some plastic deformation together and find a happy place. That is when work hardening occurs and your chain stops initially stretching. The rest of the wear would seem to be on the roller pins and faces of the rollers which is why you have to hang a weight to measure the length of the chain. That deformation that occurs on the face of the chain roller which may have not stretched because of a say, pre stretched chain or the egging of the roller itself may not be easily detected by just looking at the chain or even measuring length.
The sprocket can be worn out at an especially faster rate especially if it doesnt perfectly match the surface of the chain rollers starting the rolling wear or bulging you see which occurs on the junky aluminum sprocket variety. My theory of "Junkyard style" home grown chain measurement I have distilled for 22 years is based on first having a superior steel sprocket which never ever ever ever wears out of course. First I do a sag measurement. The chain which actually could be worn out even though it may still measure to be in the 2% range. But you say why it can never wear out it is Pre stretched and those plates are onobtanium and will never stretch, Hmm or did it already stretch and deform in length.. Second I just takes me finger and I just pull that chain back and it tells me if the chain is still in pitch, quickly. This also tells me if the rollers are making good contact with the sprocket gear tooth faces. Of course Jaybird measuring the length of the chain will tell me if the chain stretched but not if the chain rollers are eggs and wont fit in the sprocket anymore and fitting good. If the sprocket is being changed and the chain was used for any reasonably long time. I know that those sprocket rollers were deformed they have to be pal and I am not going to ruin a new sprocket by putting it on there if I cannot measure the actual rollers for wear. IF you have a theory on knowing if the rollers are worn and not just if the chain is stretched I am all ears.
I personally wouldnt trust dual material sprockets because I would guess that the shear forces are too great between the two materials. Actually they would be multiplied as the connection between them is further out from the center. That any weight savings would be lost by trying to efficiently and safely engineer a bond or connection between the two materials and actually save any weight. I need another beer now.
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The most accurate way to measure chain elongation is described in the following thread:
http://dirtrider.net/forums3/showthread.php?p=635627#post635627
You CAN measure the roller to see if it is egged. Simply take the chain off...bend the chain so that one roller is in the bend. You could then place 4 dots on the roller 90 degrees apart from each other with a marker, creating 4 equal spaces. Take your vernier caliper and measure the roller in at least 4 places...or 8 for that matter. This should confirm the concentricity of the roller.
Of the moving chain parts, the roller is the least likely to deform, due to the fact that it only moves during contact when the chain tooth is entering or exiting the reel.
This movement does create force between the inside diameter of the roller and the outside diameter of the bushing, however (assuming we are running a non-lubricated chain) the wear will occur on a very specific area of the bushing and no place else, the roller, on the other hand, can wear anywhere in the total 360 degrees of the inside diameter's face. Where the roller is when it comes in contact with the working face of the sporocket tooth is totally random and most likely will end up being a uniform wear around the inside circumference of the roller.
A roller/bushing area will indeed wear, and will in fact contribute to the elogation of the links pitch...BUT it will not effect the elongation like the wear at the pin/bushing area will.
The method I described above for measuring accounts for roller/bushing wear, but only the wear on the two rollers used for the measurement are taken into account.
Lets assume there is .005" wear on each pin/bushing area (and no wear on the roller/bushing). You measure a total of 10 pins distance and this wear will show an elongation of .05". This is because the wear is a cumulative thing and efffects the total length by a multiplier equal to the number of pins distance measured. Adding up a little wear on each part effects the total distance accordingly.
Now let's assume we have a ring chain that has no wear on the pin/bushing (due to them being internally lubricated), yet the rider has placed no lube on the chain at all and there is in fact .005" wear on each roller/bushing. The effect on the sprocket is minimal because the roller/bushing wear is not cumulative and only effects each particular reel.
This means that the sprocket tooth will see no more growth than .005" at any time, as the wear on several rollers does not effect the total length cumulatively. In other words, each roller is contained within it's individual reel and doesn't effect the total length.
Yes, this will have a minimal effect on the sprocket tooth, but the small amont of wear on the roller has far less effect than what pin/bushing wear does.
When you say you "see" the sprocket seat deforming, it will be due to the chain elongating from the pin/bushing wear, and very minimally from roller/bushing wear.
Also...too many beers makes you read things out of whack.
I never said you should run an old chain on new sprockets. I said you can run a new chain on old sprockets, if there is no visible wear on the sprockets.
Prost!
http://dirtrider.net/forums3/showthread.php?p=635627#post635627
You CAN measure the roller to see if it is egged. Simply take the chain off...bend the chain so that one roller is in the bend. You could then place 4 dots on the roller 90 degrees apart from each other with a marker, creating 4 equal spaces. Take your vernier caliper and measure the roller in at least 4 places...or 8 for that matter. This should confirm the concentricity of the roller.
Of the moving chain parts, the roller is the least likely to deform, due to the fact that it only moves during contact when the chain tooth is entering or exiting the reel.
This movement does create force between the inside diameter of the roller and the outside diameter of the bushing, however (assuming we are running a non-lubricated chain) the wear will occur on a very specific area of the bushing and no place else, the roller, on the other hand, can wear anywhere in the total 360 degrees of the inside diameter's face. Where the roller is when it comes in contact with the working face of the sporocket tooth is totally random and most likely will end up being a uniform wear around the inside circumference of the roller.
A roller/bushing area will indeed wear, and will in fact contribute to the elogation of the links pitch...BUT it will not effect the elongation like the wear at the pin/bushing area will.
The method I described above for measuring accounts for roller/bushing wear, but only the wear on the two rollers used for the measurement are taken into account.
Lets assume there is .005" wear on each pin/bushing area (and no wear on the roller/bushing). You measure a total of 10 pins distance and this wear will show an elongation of .05". This is because the wear is a cumulative thing and efffects the total length by a multiplier equal to the number of pins distance measured. Adding up a little wear on each part effects the total distance accordingly.
Now let's assume we have a ring chain that has no wear on the pin/bushing (due to them being internally lubricated), yet the rider has placed no lube on the chain at all and there is in fact .005" wear on each roller/bushing. The effect on the sprocket is minimal because the roller/bushing wear is not cumulative and only effects each particular reel.
This means that the sprocket tooth will see no more growth than .005" at any time, as the wear on several rollers does not effect the total length cumulatively. In other words, each roller is contained within it's individual reel and doesn't effect the total length.
Yes, this will have a minimal effect on the sprocket tooth, but the small amont of wear on the roller has far less effect than what pin/bushing wear does.
When you say you "see" the sprocket seat deforming, it will be due to the chain elongating from the pin/bushing wear, and very minimally from roller/bushing wear.
Also...too many beers makes you read things out of whack.
I never said you should run an old chain on new sprockets. I said you can run a new chain on old sprockets, if there is no visible wear on the sprockets.
Prost!
great post, Jaybird.
Seems like a while back I did a metallurgical analysis on some chain components, I should have documented. I do remember that the rollers were relatively hard-probably approaching 50 RC or better. My point is that they aren't going to mush around and deform very easilly. I have seen them crack and fall off, though.
The suggestion that the chain stops stretching because of work hardening action is an interesting idea, but not likely. Steels with an austenitic microstructure do work harden somewhat (304 SS would be an example, AR 400 would be a better one), but your chain is definitely not made of such a material. Your chain is made of a material with a martensitic structure, which is harder and stronger than 304 SS would ever be.
The shear forces on the interface area of a composite sprocket would be greater towards the axle, not towards the teeth, due to the mechanical advantage/leverage. Has anyone weighed/compared the composite type to a steel or an aluminum sprocket? I'm curious.
Seems like a while back I did a metallurgical analysis on some chain components, I should have documented. I do remember that the rollers were relatively hard-probably approaching 50 RC or better. My point is that they aren't going to mush around and deform very easilly. I have seen them crack and fall off, though.
The suggestion that the chain stops stretching because of work hardening action is an interesting idea, but not likely. Steels with an austenitic microstructure do work harden somewhat (304 SS would be an example, AR 400 would be a better one), but your chain is definitely not made of such a material. Your chain is made of a material with a martensitic structure, which is harder and stronger than 304 SS would ever be.
The shear forces on the interface area of a composite sprocket would be greater towards the axle, not towards the teeth, due to the mechanical advantage/leverage. Has anyone weighed/compared the composite type to a steel or an aluminum sprocket? I'm curious.
OK...Scot I want to admit a lie...well not really a lie, per se, but a misnomer.
To my limited metalurgical knowledge, the elasticity of the side plates more than likely remains quite constant. I think that when we place a tensile force against the chain that the plates will return to their normal length, providing that they haven't been forced past their yield point. My research leads me to believe that this modulas of elasticity remains constant for all steels. I have a hard time believing that it wouldn't be different for different steels, but those smarter than I, seem to claim it so.
My "lie" is telling folks that the chain stretches initially to a longer point and stays there, even though I know(or think) than not to be really true. It just sems easier for folks to grasp without going into detail on the real deal. Like I tell my kids, no matter what you say that isn't quite true, there will always be at least one person who will find you out.
(I have a sneaking suspision that Eric and Rich understand where I'm coming from on this issue) :)
What I do think is that when we place a tensile force on the chain, that the working faces of the chain undergo a very slight "tightening up". This would be due to compression of the oxide layer that is present in all metals to varying degrees.
Hardening of the surface? I, like you, doubt that. But consider the surface of a fresh piece of carbon steel from the mill...the oxide scale can literaly be flaked off with your hand. Help me on this...would it make a difference to the Brinnel ball testing a fresh piece of metal that obviously has scale, and the same piece that has been prepared with a buff from a grinder?
What I have seen in industrial size chains, both roller and rivetless forged chain, is that there is indeed a "shining up" period that the chain immediately undergoes within the first few hours of run. Granted, on forged and cast parts, this immediate change in length is more due to actual removal of very jagged asperities on the mating surfaces. But I have also seen this intitial growth take place on large size roller chain but to a much lesser degree.
I think that quality chains that have had the parts shot peened have these jagged craters, or asperities, removed during this process. Due to this alone, the growth of a chain during the initial few hours of run has to be minimal. Probably so minute, on a quality motorcycle chain, that it can be ignored, since our chain drives can tolerate a good deal of tolerence in tension; especially tolerance in the "longer" direction.
On the cracking rollers...would you contribute this to the parts being too hard? Perhaps exceeding the desired hardness during the hardning process, since a different batch of steel can vary? More of a QC issue than anything else?
Man, Scott...you are in a position to know lightyears more than me on this subject, and I am jealous. I only get to pick metalurgists brains on occasion.
To my limited metalurgical knowledge, the elasticity of the side plates more than likely remains quite constant. I think that when we place a tensile force against the chain that the plates will return to their normal length, providing that they haven't been forced past their yield point. My research leads me to believe that this modulas of elasticity remains constant for all steels. I have a hard time believing that it wouldn't be different for different steels, but those smarter than I, seem to claim it so.
My "lie" is telling folks that the chain stretches initially to a longer point and stays there, even though I know(or think) than not to be really true. It just sems easier for folks to grasp without going into detail on the real deal. Like I tell my kids, no matter what you say that isn't quite true, there will always be at least one person who will find you out.
(I have a sneaking suspision that Eric and Rich understand where I'm coming from on this issue) :)
What I do think is that when we place a tensile force on the chain, that the working faces of the chain undergo a very slight "tightening up". This would be due to compression of the oxide layer that is present in all metals to varying degrees.
Hardening of the surface? I, like you, doubt that. But consider the surface of a fresh piece of carbon steel from the mill...the oxide scale can literaly be flaked off with your hand. Help me on this...would it make a difference to the Brinnel ball testing a fresh piece of metal that obviously has scale, and the same piece that has been prepared with a buff from a grinder?
What I have seen in industrial size chains, both roller and rivetless forged chain, is that there is indeed a "shining up" period that the chain immediately undergoes within the first few hours of run. Granted, on forged and cast parts, this immediate change in length is more due to actual removal of very jagged asperities on the mating surfaces. But I have also seen this intitial growth take place on large size roller chain but to a much lesser degree.
I think that quality chains that have had the parts shot peened have these jagged craters, or asperities, removed during this process. Due to this alone, the growth of a chain during the initial few hours of run has to be minimal. Probably so minute, on a quality motorcycle chain, that it can be ignored, since our chain drives can tolerate a good deal of tolerence in tension; especially tolerance in the "longer" direction.
On the cracking rollers...would you contribute this to the parts being too hard? Perhaps exceeding the desired hardness during the hardning process, since a different batch of steel can vary? More of a QC issue than anything else?
Man, Scott...you are in a position to know lightyears more than me on this subject, and I am jealous. I only get to pick metalurgists brains on occasion.
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Right on track with the Brinell test. Two basic situations on the surface, oxides or decarb, or a mixture of both. Unless it's really heavy, oxide will have less effect on hardnes testing. Heat treated parts shouldn't have any significant decarb on the surface unless they are processed in a furnace with poor atmosphere control. On a part like a chain, the dark color may vary well be from a tempering process, and in this case the oxide layer may be more of a visual thing (little effect on mechanical properties).
So, the grinding before testing is most helpful on a part that
1. Is cast or forged with a rough surface
2. Has mill scale which hasn't been corrected with heat treat
3. Has been hardened in a furnace with a poor or no atmosphere
4. Has been tempered at a high temp with poor or no atmosphere, perhaps 1050-1250 F
Regarding the rollers cracking, this could be a result of consumer abuse, out-of-spec material chemistry, incomplete or improper hardening, or "cold" tempering.
To state that all steels share the same properties, regardless of which specific property we happen to be talking about, is a sweeping generalization. Exception: "A 10 pound chunk of steel will hurt if you drop it on your toe, regardless of it's specific chemistry".
Four most common microstructures, dependant on the steel's chemistry and heat treatment, in no particular order:
1. Pearlite/Ferrite (soft, magnetic, annealed)
2. Austenitic (soft, nonmagnetic, 304 SS etc.)
3. Martensitic (medium to hard depending on temper, magnetic, chains sprockets, 440C SS, etc.)
4. Bainitic (medium hardness, magnetic, spring steel, 1080, mower blades etc.)
Each microstructure has it's own properties relative to the others, but again two alloys even if they both have the same apparent microstructure can have significantly different mechanical properties. Also, higher carbon steels (tool steels and others) may have carbides in the structure as well, further complicating issues.
So, the grinding before testing is most helpful on a part that
1. Is cast or forged with a rough surface
2. Has mill scale which hasn't been corrected with heat treat
3. Has been hardened in a furnace with a poor or no atmosphere
4. Has been tempered at a high temp with poor or no atmosphere, perhaps 1050-1250 F
Regarding the rollers cracking, this could be a result of consumer abuse, out-of-spec material chemistry, incomplete or improper hardening, or "cold" tempering.
To state that all steels share the same properties, regardless of which specific property we happen to be talking about, is a sweeping generalization. Exception: "A 10 pound chunk of steel will hurt if you drop it on your toe, regardless of it's specific chemistry".
Four most common microstructures, dependant on the steel's chemistry and heat treatment, in no particular order:
1. Pearlite/Ferrite (soft, magnetic, annealed)
2. Austenitic (soft, nonmagnetic, 304 SS etc.)
3. Martensitic (medium to hard depending on temper, magnetic, chains sprockets, 440C SS, etc.)
4. Bainitic (medium hardness, magnetic, spring steel, 1080, mower blades etc.)
Each microstructure has it's own properties relative to the others, but again two alloys even if they both have the same apparent microstructure can have significantly different mechanical properties. Also, higher carbon steels (tool steels and others) may have carbides in the structure as well, further complicating issues.
All materials have their own specific Modulus of elasticity. One thing to remember Hardness of a material doesnt necessarily mean high tensile strength. There is a brittleness that occurs when something gets work hardened. Just look at how parts usually fail right near a weld especially if the part wasnt heat treated after welding. This is where the material became harder and more brittle. If you do tensile testing it is very interesting to watch this occur if viewed on a graph. The material will first be able to show elastic properties which is where it will return to an original point when the tension is released. The graph will show a proportional straight slanted line. After the yield strength is reached this will start plastic deformation. The graph starts to show a slightly curved line and the material will not return to its original length when released. After even more higher tension is applied the lengthening deformation suddenly stops and there is a plateau which appears on the graph the tension goes up and yet it does not lengthen. There is a hardening that occurs here in this spot. If the sample is taken out this can be proven with a hardness test done along the element in comparison and will show exactly where this occurs. Keep applying more tension the plateau stops the line starts to shoot back up and this is the point where the material will reach its upper yield strength necking occurs (which looks like taffy pulling) and then bang you are walking home. I think some surface hardening may occur if the part is buffed to a high finish which can be proven with hardness testing but surface flaking will give you a false reading and be hard to determine the actual hardness unless an area is slightly grinded smooth. I broke an RK Xring two weeks ago the plates pulled apart like taffy right in the middle of the master link. The chain is not stretched beyond the 2% limit but it is halfway there. I think this initial stretching up to the yield strength is what occurs to a chain somewhat if it isnt a very good chain like someone posted the chain it will initially stretch and then stop. I picture this graph sitting in front of me. In reality It probably does go through some sort of seating in before stretching. I always replace my chain if I am replacing my sprocket cause I feel the worn chain is riding higher on the tooth of the sprocket and I feel that those ten rides or so it takes to get there will wear the new sprocket to that point almost immediately. Of course I dont change the sprocket if it is not worn out yet. I was on my third chain on my last set of sidewinders and second front sprocket but the rear sprocket showed no signs of wear yet. I sold that bike before I could tell if it would ever wear out.
This chain just simply broke while you were riding?
Why do you think the chain broke? No graphs, just plain english. Punctuation optional.
Why do you think the chain broke? No graphs, just plain english. Punctuation optional.
Greenbean-interesting post, you brought back memories of fighting to stay away in class. For some reason this stuff is more interesting now.
Please find a way to split your posts up into paragraphs! Just hit the return key a few times when it seems appropriate. People are much more likely to read your post that way. :)
Please find a way to split your posts up into paragraphs! Just hit the return key a few times when it seems appropriate. People are much more likely to read your post that way. :)
Would it be considered a bad thing to be able to tie one's chain into a knot? :thumb:
http://www.geocities.com/bobsbobstore/chain.html
I can make about 3/4 of a circle out of this thing (sideways, a.k.a. perpendicular to the normal chain "hinge" direction) when not knotted...it came off my 1975 Honda MR175
http://www.geocities.com/bobsbobstore/chain.html
I can make about 3/4 of a circle out of this thing (sideways, a.k.a. perpendicular to the normal chain "hinge" direction) when not knotted...it came off my 1975 Honda MR175
Wow...I didn't know Vic was selling chains way back then! (evil grin)
It has been close to 15 years since that class. That stuff just seems so much more interesting now for some reason :)
I just start typing an idea out and before I know it it is a page long. Sorry about the long post but I dont think too many people will find it very interesting. Just replace it when it wears out!!
I actually did a bad thing (maybe). I rode about 5 or 6 times and then I replaced the 48 tooth sprocket with a 52 and a new chain, an RK X-ring. I think it was a 114 link. Well that is just barely one link short and I wanted to ride. I had a brand new piece of chain from Krause racing and I cut a link out of that chain and used an extra masterlink from that chain (brand new) it was all the same size chain but now I had two masterlinks on it. Is that really that bad I have seen it done a lot. I have been riding it for a while like this maybe 5 months. The chain has stretched a bit in that time probably three or four notches on the adjuster. after I wash the bike I shoot it with WD-40 and then occasionally lube it with some spray chain wax.
I was navigating a tricky, rocky, but not very steep hill when the chain just broke. The sideplates broke/ripped in half I sensed it immediately and pulled the clutch. the chain still stacked up pretty good by the shifter so I couldnt get it in neutral right away and it took some effort to free it trying to turn the sprocket with the clutch pulled. I got it out and put on a spare master link I carry with me and limped back to the truck. Whats funny is a Mtn biker was walking down the same hill with a severely tacoed front wheel on his broken bike hehe. Good thing I run a Fastway case saver I thought cheap insurance for me. I did inspect the broken pieces I found and the new link that was put in there was noticably deformed on both sides. The holes were oval now.
The chain is stretched enough that it now fits without the spare link. I just needed two notches more to fit it originally. So I am now wondering if it is ok to run it like that till I wear out the rear Sprocket. The chain is still OK in length barely but I dont care about the sprocket I want a 50 on there now anyway.
I just start typing an idea out and before I know it it is a page long. Sorry about the long post but I dont think too many people will find it very interesting. Just replace it when it wears out!!
I actually did a bad thing (maybe). I rode about 5 or 6 times and then I replaced the 48 tooth sprocket with a 52 and a new chain, an RK X-ring. I think it was a 114 link. Well that is just barely one link short and I wanted to ride. I had a brand new piece of chain from Krause racing and I cut a link out of that chain and used an extra masterlink from that chain (brand new) it was all the same size chain but now I had two masterlinks on it. Is that really that bad I have seen it done a lot. I have been riding it for a while like this maybe 5 months. The chain has stretched a bit in that time probably three or four notches on the adjuster. after I wash the bike I shoot it with WD-40 and then occasionally lube it with some spray chain wax.
I was navigating a tricky, rocky, but not very steep hill when the chain just broke. The sideplates broke/ripped in half I sensed it immediately and pulled the clutch. the chain still stacked up pretty good by the shifter so I couldnt get it in neutral right away and it took some effort to free it trying to turn the sprocket with the clutch pulled. I got it out and put on a spare master link I carry with me and limped back to the truck. Whats funny is a Mtn biker was walking down the same hill with a severely tacoed front wheel on his broken bike hehe. Good thing I run a Fastway case saver I thought cheap insurance for me. I did inspect the broken pieces I found and the new link that was put in there was noticably deformed on both sides. The holes were oval now.
The chain is stretched enough that it now fits without the spare link. I just needed two notches more to fit it originally. So I am now wondering if it is ok to run it like that till I wear out the rear Sprocket. The chain is still OK in length barely but I dont care about the sprocket I want a 50 on there now anyway.
Bean...dewd....
Please don't take this the wrong way, but you have no business entering into a discussion about the intricacy's of chains and sprockets, other than ASKING questions.
How can you possibly think that anyone would find any validity to your previous posts after reading what you just posted?
You were worried about a roller being slightly egged? Come on.
Please don't take this the wrong way, but you have no business entering into a discussion about the intricacy's of chains and sprockets, other than ASKING questions.
How can you possibly think that anyone would find any validity to your previous posts after reading what you just posted?
You were worried about a roller being slightly egged? Come on.
if one of the links in the chain catastrophically failed, imagine the condition of the rest of the system?
I just thought of a story to share...one time I was getting ready to sell a KTM 495. This bike had mucho power, even by today's standards. It obviously needed a chain, but I was selling it so I bought a $19.95 Dennis Kirk special. The bike made it about 5 minutes before literally pulling apart the brand new chain. The plates came off of the pins. Lesson: there is a difference between chains, and the more power you have, the more critical the chain.
I just thought of a story to share...one time I was getting ready to sell a KTM 495. This bike had mucho power, even by today's standards. It obviously needed a chain, but I was selling it so I bought a $19.95 Dennis Kirk special. The bike made it about 5 minutes before literally pulling apart the brand new chain. The plates came off of the pins. Lesson: there is a difference between chains, and the more power you have, the more critical the chain.